- Update to 2.4.58:
*) SECURITY: CVE-2023-45802: Apache HTTP Server: HTTP/2 stream
memory not reclaimed right away on RST (cve.mitre.org)
When a HTTP/2 stream was reset (RST frame) by a client, there
was a time window were the request's memory resources were not
reclaimed immediately. Instead, de-allocation was deferred to
connection close. A client could send new requests and resets,
keeping the connection busy and open and causing the memory
footprint to keep on growing. On connection close, all resources
were reclaimed, but the process might run out of memory before
that.
This was found by the reporter during testing of CVE-2023-44487
(HTTP/2 Rapid Reset Exploit) with their own test client. During
"normal" HTTP/2 use, the probability to hit this bug is very
low. The kept memory would not become noticeable before the
connection closes or times out.
Users are recommended to upgrade to version 2.4.58, which fixes
the issue.
Credits: Will Dormann of Vul Labs
*) SECURITY: CVE-2023-43622: Apache HTTP Server: DoS in HTTP/2 with
initial windows size 0 (cve.mitre.org)
An attacker, opening a HTTP/2 connection with an initial window
size of 0, was able to block handling of that connection
indefinitely in Apache HTTP Server. This could be used to
exhaust worker resources in the server, similar to the well
known "slow loris" attack pattern.
This has been fixed in version 2.4.58, so that such connection
are terminated properly after the configured connection timeout.
This issue affects Apache HTTP Server: from 2.4.55 through
2.4.57.